Riverine and Sediment Processes in the Yangtze River – Modeling and Validation

The sediment flux from Yangtze River into the estuary area decreased during the past three decades and the operation of world’s largest hydropower project, Three Gorges Dam, made this situation much more severe. In the delta area, another project called Deep Water Navigation Channel was also completed in 2011. To document impacts of these two projects on estuarine hydrodynamics and morphology changes, in this study, we used the Delft3D flow module to investigate the hydrodynamic and sediment transport processes. Several islands and shoals in the Yangtze Estuary region were located near Deep Water Navigation Channel and their shoreline changes were tightly coupled with the sediment flux from Yangtze River. The evolution of the geometry and elevation of these islands and shoals in the river are used as metrics to gauge the effect of the manmade changes to the Yangtze River Delta, as well as predict future changes and effects.